package io.gitee.xyuesheng.day05;

import org.junit.Test;

public class TestObject {
    @Test
    public void test() {
        Boss b = new Boss();

        System.out.println(b);
    }

    @Test
    public void testEQuals() {
        String s1 = "abc";
        String s2 = "bcd";

        //判断两个对象，==，判断两个引用地址是否相等
        System.out.println(s1 == s2);

        String s3 = "abc";//abc在常量池里面，是一个对象
        System.out.println(s1 == s3);

        String s4 = new String("abc");
        System.out.println(s3 == s4);
        //equals:判断对象的内容是否相等
        System.out.println(s3.equals(s4));
    }

    @Test
    public void testStudent() {
        Student s = new Student("黄", 18, "1001");
        Student s2 = new Student("黄", 18, "1001");
        Student s3 = new Student("黄", 20, "1001");
        Student s4 = s;
        Student s5 = new Student();
        Student s6 = new Student();

//        HomeworkStudent s7=null;
//        s7.getAge();//报空指针异常

        System.out.println(s.equals(s2));
        System.out.println(s.equals(s3));

        System.out.println(s.equals(s4));
        System.out.println(s5.equals(s6));
    }

    @Test
    public void testNull() {
        System.out.println(null instanceof Student);
    }

    @Test
    public void testStringHash() {
        String s1 = "abc";
        String s2 = "abcd";

        System.out.println(s1.hashCode());
        System.out.println(s2.hashCode());


    }


}
